A Geoelectrical Investigation of Groundwater Potentials in Dorowa and its Environs, Plateau State, North Central Nigeria

Abstract

A geoelectrical investigation for potable groundwater potentials in Dorowa and its environs, Plateau State, North Central Nigeria has been carried out. The area is part of Jos-Bukuru Younger Granite Complex and is underlain by seven main rock types namely: Vom Microgranite (Vm), Rayfield Gona Biotite Granite (RGB), Ngell Biotite Granite (NGB), Vom Hornblende Biotite Granite (VHB), Shen Hornblende – Fayalite Granite (SHF), Porphyritic Biotite Granite (PBG) and Jos Biotite Granite (JBG). Interpretation of field structures and GIS data reveal lineaments trending NW-SE and NE-SW. Vertical electrical soundings conducted within Ngell biotite granite reveals that the area is underlain by three geoelectric layers. The top layer is mainly made up of laterite at depth between 0 - 5 m with resistivity values ranging from 79 – 202 Ωm, the second layer is made up of weathered granite at depth between 3 – 16 m with resistivity between 46 - 396 Ωm and the third layer is made up of slightly weathered to fresh granite at depths greater than 4 m with resistivity greater than 113 Ωm. The zones of medium groundwater potential vary from 15 -16 m. Weathering depth in areas of fair water potentials varies from 13m – 14m with the best water potentials on VES 10 and VES 6. Zones of low groundwater potentials cover most part of the study area at depth less than 12m.